Rheumatoid arthritis is a chronic inflammatory disease affecting multiple tissues, but typically producing its most pronounced symptoms in the joints. It is progressive, degenerative and ultimately debilitating. The chronic inflammation in joints leads to the destruction of the soft tissue, the synovium and cartilage, as well as erosion of the articular surfaces of bones. The disease is estimated to affect over 3.2 million people in the United States, Europe and Japan. It is more prevalent in women, who are estimated to account for a majority of the cases.
Inflammation is a natural defense of the body to protect against foreign substances or injury, but it can cause problems in certain diseases. Inappropriate inflammation can be treated with traditional steroids, like the glucocorticoid cortisol, therapeutic proteins produced by recombinant DNA technology, and/or non-steroidal anti-inflammatory drugs (NSAIDs).
Prostaglandins are a family of chemicals that are produced by the cells of the body and serve many essential functions including the promotion of pain, inflammation, and fever. Additionally, some prostaglandins support the function of platelets, necessary for blood clotting, and protect the stomach lining from the damaging effects of acid. Prostaglandins are produced within the body's cells by the enzyme cyclooxygenase-2 (COX-2).
COX-2 is an enzyme involved in many functions, including but not limited to inducing pain. COX-2 is located specifically in areas of the body that are responsible for inflammation and not in the stomach. COX-2 is active in our bodies, ideally on a limited basis; however, factors such as diet, stress and injury can increase COX-2 activity. When COX-2 is active on a continual basis, constant pain ensues.
Even though the specific mechanism of action is not completely understood, it has been found that inhibiting COX-2 results in the apoptosis of cancer cells. See Johnsen, et al., “Cyclooxygenase-2 Is Expressed in Neuroblastoma, and Nonsteroidal Anti-Inflammatory Drugs Induce Apoptosis and Inhibit Tumor Growth In Vivo,” Cancer Research; Vol. 64, pages. 7210-7215 (Oct. 15, 2004); and Lau, et al., “Cyclooxygenase inhibitors modulate the p53/hdm2 pathway and enhance chemotherapy-induced apoptosis in neuroblastoma,” Oncogene, Vol. 26, pages 1920-1931 (2007).
Therefore, plant extracts that may inhibit COX-2 may treat various diseases, including but not limited to inflammation, arthritis, muscle pain, and cancer.